Depth gauge and scarifier for a bulldozer blade



March 17, 1964 c. JEFFREY DEPTH GAUGE AND SCARIFIER FOR A BULLDOZER BLADE Filed April 5, 1962 FIG.

INVENTOR CLARENCE L. JEFFREY ATTORNEY United States Patent G l 3,124,888 DEPTH GAUGE AND SCARIFIER FOR A BULLDGZER BLADE Clarence L. Jeffrey, 814 W. Center St., Fairfield, Ill. Filed Apr. 5, 1962, Ser. No. 185,462 1 Claim. (Cl. 37-145) This invention pertains to improvements in earth moving or earth working machines generally, and more particularly it pertains to improvements in the construction of a bulldozer blade.

One of the several objects of the invention is to provide a machine of this type with a. multitude of earth scarifying teeth or loosening and ripping spikes.

Another object of the invention has to do with the shaping of the scarifying teeth. I have shaped the teeth in the form of an L or a J, and so mounted them on the blade of the bulldozer as to form a depth gauge of the teeth.

An additional object of the invention is to provide an arrangement of scarifier teeth so that they may be used as a depth gauge on the forward movement, that is, the cutting movement of the bulldozer blade.

An additional object of the invention is to make the scarifier teeth on the bulldozer blade self-sharpening.

Another object of the invention is to provide an arrangement of scarifying teeth for a bulldozer blade which will make them work for scarifying only on the rearward movement of the bulldozer blade, so that they will not scarify the earth which is closely packed, or break it up on the forward movement.

With these and other objects and advantages in mind, the invention resides in the certain new and useful combination, construction, and arrangement of parts, as will be hereinafter more fully described, set forth in the appended claim, and illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective view of the bulldozer blade in the erect or cutting position, showing the scarifier teeth in position as a depth gauge;

FIGURE 2 is a side elevational view showing the bulldozer blade in the tilted or ripping position, showing the scarifier teeth in their earth-loosening position;

FIGURE 3 is a rear elevational view showing the end scarifier tooth of FIGURE 1, mounted on a cutaway portion of the bulldozer blade; and

FIGURE 4 is a top plan view of the bulldozer blade of FIGURE 1.

Referring to the drawings, wherein like characters of reference denote corresponding parts in the several views. In FIGURE 1 the bulldozer blade is given the numeral 1. The blade is shown in the erect or cutting position which is used for forward movement of the bulldozer. The scarifying teeth are shown mounted on the back of the blade 1. The teeth are made of hardened steel and may be welded or bolted to the back of the blade 1. I have illustrated them as welded to the blade. The end tooth is numbered 2, and the others, spaced at even intervals along the blade, are numbered 3, 4, and 5.

Each scarifying tooth is formed like the letter J or L, by which I mean that its lower portion is bent perpendicular to the body of the tooth, as at 6. The result of this bending of the shape of the scarifying tooth is to form the leg 7 which is sharpened at the tip.

The fact that the leg 7 is perpendicular to the body of the scarifying tooth means that in the position of FIGURE 1, the leg 7 and the lower edge 8 of the bulldozer blade 1 are exactly even and form a horizontal line. This horizontal line, I have illustrated in the drawing of FIGURE 1 as a dotted line. This dotted line represents the earth cutting line.

In operation, my improved scarifier teeth have a num- 3,124,838 Patented Mar. 17, 1964 her of advantages which are not immediately apparent, but which are together a significant departure from the present conventional practice.

When the operator wishes to cut earth to a certain depth, he merely lowers the blade to the approximate position. Then he tilts the blade with his pitch control, or his tilt control as he may call it, until the blade is in the position shown in FIGURE 1.

The operator will be able to find this erect or cutting position very easily in the following manner: Let us assume that the blade has been in the position of FIG- URE 2. In this position the leg 7 of the tooth 2 has been ripping in the earth.

Tilting this blade forward, that is rotating the blade around the bottom edge 8 clockwise in FIGURE 2 will bring the blade closer to the position of FIGURE 1. As the blade more and more is tilted to the position of FIGURE 1, the leg 7 will be more and more drawn out of the earth. Consequently the leg 7 will, when it finally reaches the position of FIGURE 1, no longer leave a mark when moving forward behind the edge 8.

Similarly, if the blade has been tilted clockwise past the position of FIGURE 1, reversal of the pitch control or the tilt control can be carried on until the leg 7 barely begins to make a mark behind the lower cutting edge 8. When the leg 7 and the edge 8 are exactly horizontal, the leg 7 will not leave a mark behind the edge 8 on the forward movement of the blade cutting earth Thus the leg 7 has been employed as a depth gauge to determine the proper tilt angle to be given to the bulldozer blade 1. At the same time the leg 7 can be better seen by the operator of the bulldozer than can the cutting edge 8. Consequently once the blade 1 is tilted at the proper angle for forward cutting, the operator has only to watch the outside legs 7 of the teeth 2 and 5 in order to gauge the depth of the cut which he is taking on the forward movement.

The tilting of the blade is generally accomplished conventionally by the use of hydraulic rams, in the form of a hydraulic piston and cylinder attached to the top of the bulldozer blade. Now the rearward movement of the blade will be described. When the blade is moved rearward, it is an advantage to rip up or otherwise loosen the earth which is to be out free on the forward movement of the bulldozer blade.

I prefer to tilt the blade 1 to the position shown in FIGURE 2, by moving the top of the blade 1 counterclockwise around the edge 8, that is the reverse movement of that described above. In such movement the teeth assume the position shown in FIGURE 2 with the leg 7 embedded in and traveling through the earth. The earth line is again represented by the horizontal dotted line at the bottom of FIGURE 2, and it will be seen that the leg 7 which it bent at an angle vertical to the body of the tooth 2, is lower than the dotted line. The measure of the tilt is the amount the tooth leg 7 lies below the cutting edge '8.

The cutting edge or cutting point of the leg 7 is self sharpening as will be illustrated in the following manner: When traveling forward in the position of FIGURE 1, the leg 7 is sharpened on the bottommost edge which lies against the earth or ground. When traveling backward in the position of FIGURE 2, the cutting tip is sharpened.

With a minimum of instruction and practice the operator becomes surprisingly adept at tilting the blade forward when preparing for forward movement and cutting by the blade. Thus he tilts the blade forward just till the leg 7 does not leave a mark on the earth cut by the edge 8. He then makes his cut with the blade.

Then he stops the bulldozer, tilts the blade backward to the position of FIGURE 2 and then runs the bulldozer backward, to loosen the earth in the working area, ripping the earth loose with the teeth 7. He is then ready to stop the bulldozer and begin his forward out again with the blade, first tilting the blade to the position of FIGURE 1.

Successive repetitions of the cycle of tilting the blade forward and backward to correspond to the forward and backward movement of the blade and bulldozer accomplishes the cutting of a great deal of earth free with a minimum of difliculties.

The use of hinged scarifier teeth which drag loosely on the back of a blade when moving forward but which fall against the blade itself and are used in ripping on the backward movement has been tried, along with other expedients. However none of these arrangements is entirely satisfactory since the depth of the cut and the depth of the ripping movement cannot be gauged conveniently. With the use of my arrangement all these objects can be accomplished quite easily and economically.

Without further description, it is obvious that many additional advantages are to be had from the disclosed embodiments of my invention, as will be apparent to those skilled in the art. Also it is to be understood that the number of scarifying teeth to be used in combination with any particular dozer blade will be governed materially by its length, while the exact manner of attaching the scarifying teeth and positioning them will be determined somewhat by the manner in which the bulldozer blade is supported by the tractor, since there must be no interference. It is to be further understood that any and all changes in form, construction and arrangements of parts, to which my invention is susceptible, may be made without departing from the spirit of the invention, or its scope as claimed.

What I claim is:

The combination consisting of a scarifier tooth and depth gauge mounted upon a tiltable bulldozer blade hav ing a lower cutting edge, consisting of a metal body which is mounted integrally with said blade on the back thereof, and a leg formed to project at an angle perpendicular to the body of said scarifier tooth, said perpendicular leg positioned so that its lowermost surface is in the same plane as the lower cutting edge of said blade and terminating in a sharpened point projecting rearward of said blade and positioned to be rotated above and below said cutting edge when the bulldozer blade is tilted clockwise or counterclockwise.

References Cited in the file of this patent UNITED STATES PATENTS 628,800 Helling July 11, 1899 1,195,271 Ruth Aug. 22, 1916 1,435,920 Greenleaf Nov. 21, 1922 1,763,373 Schnell June 10, 1930 2,243,127 Roseman May 27, 1941 2,279,869 Houston Apr. 14, 1942 2,421,472 Way June 3, 1947 

